Assessing our water footprint

Aug 2009

Sweden

Climate change, rapid population growth
and unsustainable practices are putting our
water resources at risk.
Whether it is the fuel that makes our cars
run or the packaging that keeps our food
fresh, the products we use every day require
a large amount of water to produce.
In a water stressed world, the water footprint
of products will be a key environmental
indicator in the drive towards an increased
sustainable development.
For the first time, Borealis and the Swedish
Royal Institute of Technology (KTH) have
investigated the water footprint of plastics
materials.

Besides the water we use for drinking, cooking or washing, we also
need water to produce goods we daily use: from the farm to your
cup the coffee you drank this morning required an average of 140
litres of water to make. Your cotton shirt may have taken another
2,700 litres while a single sheet of A4 paper would “weight” 10
litres.

On average, agriculture accounts for 70% of fresh water use, industry
20% and our domestic use 10%. Most research has therefore focused
on our food and drink footprint, but little is known about
industrial products or materials like plastics that are used in many
applications and value chains.

Yet, like any industrial process, the production of petrochemicals
and plastics requires water for cooling, processing and cleaning.
To account for the water “embedded” in our goods, leading academics
Professor A. Allan, Laureate of the 2008 Stockholm Water
Prize, and Professor A. Hoekstra from Tweente University, developed
the water footprint, which measures the amount of water used from
raw material production to the manufacturing of the finished
product.

In 2008, Borealis piloted the concept to estimate the footprint of a
domestic plumbing system with its key customer Uponor. This pilot
pointed to the need for more robust methodologies and better assessment
of water use for plastics manufacturing, notably for supplies
and energy.

Measuring real water use

Unlike the usual abstraction measures, a water footprint reports the
actual volume of fresh water removed from a local water body – a
river, lake or groundwater table – and not returned to it at proper
quality standards. This water will no longer be available for local
eco-systems or other users. The total water footprint of a business
is the combination of the direct water footprint of its operations
along with the (indirect) footprint of its supplies and energy consumption
(see graph).

To measure its exact direct water footprint, Borealis has been working
with the Swedish Royal Institute of Technology (KTH). The direct
water footprint was calculated on the basis of a detailed review of
the water flow in manufacturing processes and at production
sites.

This review concluded that Borealis’ direct water footprint was
17,900 million m³ in 2008. For products, one kilogram of polyolefin was assessed to have a direct water footprint ranging from 1.2 to
6.5 litres per kg of finished product.

While the company’s direct water footprint remains limited, its indirect
footprint from energy and feedstock consumption could increase
up to 40 mm³ with the use of more water-intensive feedstock (e.g.
natural gas, which has a much lower footprint than oil refinery output)
or energy sources for electricity (e.g. hydro-power, which has a higher
footprint than nuclear or coal). Data on energy sources and feedstock
water footprint, still require further investigation.

Assessing the impact of a water footprint

While a carbon footprint has a global impact, a water footprint must
be assessed at the local level; the footprint in a water-stressed
environment would have a higher impact than in a water-rich
environment.

To assess its impact, Borealis mapped its plants’ water footprint
against the local water stress index and made projections up to the
year 2025 using on-line systems like the WBCSD global water tool.
With the assistance of local water experts, this assessment will help
plan for future sustainable water management actions.

“Water footprinting” is part of Borealis’ and Borouge’s commitment
to advance best practices in sustainable water management. It sets
a key indicator for all industries to better assess environmental
performance alongside energy and carbon footprint. Building upon
this experience, Borealis and Borouge will work together to further
apply “water footprinting” in their value chains and share the concept
with industry partners.